Grate construction



Ju'rie 6, 1933. 5 THOMPSON 7 1,912,869

GRATE CONSTRUCTION Filed March 4, 1930 A'ITORN EYf Patented June 6,1933

UNITED STATES PATENT OFFICE jaAivrns s. THOMPSON, OF NEW noorrnLLn, NEWYOBK, AssIeNoa T FIREBAR con-ronarrow, or CLEVELAND, onro, A CORPORATION or DELAWARE GRATE corvsrnccrrorr Application filed. March 4, 1930. Serial: No. 432,997.

mThis invention relates to grate constructions of the typeused in locomotives, marine boiler furnaces, and for other similar heavy duty purposes. More 'particularlythe invention is concerned with a grate construction which includes a grate frame and grate bars, these parts being so constructed and arranged that all parts of the fuel bed supported thereon receive air suflicient for combustion.

In my co-pending application Serial No. 431,282 filed February 25, 1930, I have set forth the disadvantages inherent in grate constructions in the form now in common use, these disadvantages resulting from the failure of the builders to appreciate that the top of thegrate frame supports a substantial part of the fuel bed. In the ordinary grate made up of a frame and grate bars supported therein, the bars are provided with means for the passage of air therethrough to the fuel, but the members of the frame have imperforate tops so that fuel carried thereon does not receive the air in the amount re- V quired for combustion and as a consequence,

it burns sluggishly with the formation of clinkers and loss of fuel. The dead area represented by the top of the frame members in a grate of standard size may amount to as much as 15 per. cent. of the total overall.

area of the grate and the failure to supply air tothe fuel on the frame results in a substantial lessening of the efficiency of the grate. I 5 In my copending application, I have disa closed a grate construction in which these disadvantages are overcome. In that grate,

the frame is provided with fuel-supporting units which in some respects resemble parts of grate bars and these units are provided with means for the flow of air to the fuel which they support. The present invention based on the same principles as are involved in the construction shown inthe copending application but the present grate differs from the one of the application in various respects which simplify the manufacture and to someextent prolong the life. a In the new grate, there is a grate frame anda plurality of bars mounted thereonion trunnions. This frame may be made up of a pair of side members and one or more center members, depending on the size of the fire box. Each frame member is provided at its top with spaced pockets in which fuel-supporting units are detachably. mounted, these units seating in the pockets and being held firmly in place therein. Each unit comprises a plate having a plurality of spaced lugs along opposite faces thereof, the lugs defining upward passages for the flow of air. Each lug has at its top a fuel supporting surface which is subdivided by intersecting air channels to form a plurality of small fuelsupporting areas and the channels communicate with the passages so that air is distributed on all sides of each area andis thus supplied to the fuel thereon. Each unit is provided at its midpoint with a socket for receiving the trunnion of the grate bar and when the units are in place, the grate presents a substantially continuous surface throughout the fire box, at all parts of which air is supplied to the fuel in the amounts required for combustion.

For a better understanding of the invention, reference may be had to the acc0mpanying drawing, in which Fig. 1 is a view of a frame member in side elevation;

Fig. 2 isa fragmentary plan view of a part of a complete grate;

Fig. 3 is a viewin side elevation of aportion of a frame member;

Fig. 4. is a sectional view on the line 4-4:

10 of which only one is shown, a center frame member 11,'and grate bars l2mounted in a side frame member and the center frame member, respectively. In the average grate, there may be a single center frame member so that there are two sets of grate bars, while in larger fire boxes, there may be two center frame members and three sets of grate bars. The bars of each set are connected to a common shaker rod so that they may be rocked in unison. Grate bars of standard construction may be utilized in the new grate, but I prefer to employ the bars illustrated in the co-pending application of Buckley, Serial No. 338,352 filed February 8, 1929, now Patent No. 1,884,557, October 25, 1932, because of the more efIicient combustion afforded by the use of the Buckley bar. 7

Each frame member comprises a web 13 and a bottom flange 14, the top of the web being provided with pockets '15 at spaced interva-lsalong it; Each pocket is defined by a rib 16, this ribhaving an inwardly projecting portion 17 from'each end thereof. Mounted in each pocket is a fuel-supporting element 18, this element comprising a plate having a downwardly extending tongue 19 at its lower end which is received in the pocket and held against lateral displacei'nent by the inwardly projecting portions 17 of the rib 16. The plate is provided with a row of spaced lugs 20 extending downwardly from its upper edge, adjacent lugs between them delinlng a passage 21 for the upward flow of air. At the top of each lug there may be an upwardly extending projection 22, in the 'top of which are formed intersecting air adapted to receive a trunnion 27 of a grate bar 12. I

In thecenter frame member (Fig. 4-) the pockets 15 are arranged in pairs throughout the lengthof the bar and in each pocketthere is mounted a fuel-supporting unit 18. These ening ribs 16 and are held'in place by, the

inward extensions 17 of the rib. The units are spaced at the top by spacing lugs 28 formed as portions of the lugs 20 and when in proper position, the fuel supported on the surfaces of the units receives air which flows up through the passages between adjacent lugs on the faces of the units and also in the space between the units. In a side frame member, such as is illustrated in Fig. 6, the

porting element when in normal position lies in contact with a portion of the web, as shown in F ig. 1. In Fig. 7 there is illustrated a modified form of the construction in which the web 13 is cut away above the bottoms of the pockets and fuel-supporting elements 29 of a different construction are employed. Each of these elements is provided at its lower end with an offset flange 30 and when a pair of elements are mounted in a pocket in the center frame member, they are placed so that the flanges extend toward one another as shown in Fig. 7. These flanges, together with the spacinglugs 28, serve to maintain the elements in normal upright position. The construction shown in Fig. 7 is somewhat simpler to manufacture so far as the frame member is concerned.

It will be seen that with the grate construction described, fuel supported above the grate frame on the fuel-supporting units receives air quite as effectively as the fuel supported on the grate bars. As a consequence, the fuel. carried by the frame burns with good combustion and by the elimination of the dead surface ordinarily presented by the area of the top of the grate frame, the effectiveness of the grate as a whole is substantially increased. Also, the cost of maintenance of the equipment is reduced and installation charges are lowered. lVith the present construction, the frame members are of much less weight than those of the present "able, the frame members may be installed individually and the fuel-supporting units mounted in place thereafter. Afterthese 'units are in place, the grate bars are inserted in them in the ordinary manner. Since the fuel-supporting units are the only part of the grate frame which comes in contact with the fuel bed and these units are small and easily replaced, any injury to a 'unit does notresult in a substantial loss of metal as is the case when an ordinary grate frame burns out. Also, the labor charges units rest on thelr lower ends on the'strengthin making the repairs are relatively small.

.WVhat, I claim is:

' 1. A grate which comprises frame members, each having a plurality of pockets along the top thereof arranged in a row lengthwise of said member, fuel-supporting units carried by said members, each unit comprising a' plate, spaced vertical lugs on at least one side of said plate extending down from the top of the plate and providing air passages, an open top trunnion socket on the top edge of said plate, and a tongue project-v ing down from the lower edge of the plate and entering a pocket in said member, the

lower edge of the plate on either side of said tongue'bein spaced above the top of said member, and grate bars each having trun- 1 nions entering sockets in said members.

2. A grate which comprises frame members each consisting of a web having a row of pockets along its upper edge, fuel-supporting units carried by said members, each unit comprising a plate having a trunnion socket in its upper edge, said socket being defined in part by a rib projecting laterally from said plate, spaced vertical lugs projecting laterally from at least one face of said a plate and lying on oppositesides of said socket, a tongue projecting down from the lower edge of said plate and entering a pocket in one of said members, and grate bars each having arms at its ends and trunnions projecting from said arms and entering said sockets said ribs on said units providing stops cooperating with said arms to maintain said bars in proper endwise position.

3. A grate which comprises frame members each consisting of a web having a row of pockets along its upper edge, each pocket being defined by one face of said web and by a rib projecting laterally from said face, fuel-supporting units carried by said members, each unit comprising a plate having an open trunnion socket in its upper edge defined in part by a rib projecting laterally from said plate, a tongue projecting down from the lower edge of said plate and entering a pocket in one of said members, said rib on said unit extending out beyond the plane of said face of said Web at least as far as the rib on said web, and grate bars each having trunnions entering said sockets, said ribs on said units providing stops cooperating with portions of said bars to maintain said bars in proper endwise position.

In testimony whereof I affix my signature.

JAMES S. THOMPSON. 

